1. Field
The present disclosure relates to a flexible display and a manufacturing method thereof.
2. Description of the Related Technology
A thin film transistor (TFT) has been used in various fields, including as a switching and driving element in a flat display device such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, and an electrophoretic display.
The thin film transistor typically includes a gate electrode connected to a gate line transferring a scan signal, a source electrode connected to a data line transferring a signal to be applied to a pixel electrode, a drain electrode facing the source electrode, and a semiconductor electrically connected to the source electrode and the drain electrode.
A semiconductor of the thin film transistor is generally formed of amorphous silicon or crystalline silicon. The amorphous silicon may be deposited at a low temperature to form a thin film, thereby being widely used in a display device mainly using glass having a low melting point as a substrate, and the crystalline silicon has electrical characteristics of high field effect mobility, a high frequency operation characteristic, and a low leakage current.
In order to form the thin film transistor on the substrate, a buffer layer for preventing an impurity and the like from entering the thin film transistor is typically required.
However, in a case where the buffer layer contains a large amount of hydrogen, failure of the thin film transistor due to, for example, a film tearing phenomenon, is generated during a process for crystallizing the semiconductor of the thin film transistor.
Further, hydrogen exhibits different hydrogen passivation effects according to a position of the substrate, to cause a non-uniform element characteristic.
Additionally, in a case where a flexible display is manufactured like the organic light emitting diode display, the buffer layer may be separated from the substrate by repeated bending due to a characteristic of the flexible display.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.